1 #ifndef PROTOCOL_H 2 #define PROTOCOL_H 3 4 #include <stdint.h> 5 #include <stddef.h> 6 #include "signal_protocol_types.h" 7 8 #ifdef __cplusplus 9 extern "C" { 10 #endif 11 12 #define KEY_EXCHANGE_INITIATE_FLAG 0x01 13 #define KEY_EXCHANGE_RESPONSE_FLAG 0X02 14 #define KEY_EXCHANGE_SIMULTAENOUS_INITIATE_FLAG 0x04 15 16 #define CIPHERTEXT_UNSUPPORTED_VERSION 1 17 #define CIPHERTEXT_CURRENT_VERSION 3 18 19 #define CIPHERTEXT_SIGNAL_TYPE 2 20 #define CIPHERTEXT_PREKEY_TYPE 3 21 #define CIPHERTEXT_SENDERKEY_TYPE 4 22 #define CIPHERTEXT_SENDERKEY_DISTRIBUTION_TYPE 5 23 24 /* Worst case overhead. Not always accurate, but good enough for padding. */ 25 #define CIPHERTEXT_ENCRYPTED_MESSAGE_OVERHEAD 53 26 27 int ciphertext_message_get_type(const ciphertext_message *message); 28 signal_buffer *ciphertext_message_get_serialized(const ciphertext_message *message); 29 30 int signal_message_create(signal_message **message, uint8_t message_version, 31 const uint8_t *mac_key, size_t mac_key_len, 32 ec_public_key *sender_ratchet_key, uint32_t counter, uint32_t previous_counter, 33 const uint8_t *ciphertext, size_t ciphertext_len, 34 ec_public_key *sender_identity_key, ec_public_key *receiver_identity_key, 35 signal_context *global_context); 36 37 int signal_message_deserialize(signal_message **message, const uint8_t *data, size_t len, 38 signal_context *global_context); 39 40 int signal_message_copy(signal_message **message, signal_message *other_message, signal_context *global_context); 41 42 ec_public_key *signal_message_get_sender_ratchet_key(const signal_message *message); 43 44 uint8_t signal_message_get_message_version(const signal_message *message); 45 46 uint32_t signal_message_get_counter(const signal_message *message); 47 48 signal_buffer *signal_message_get_body(const signal_message *message); 49 50 /** 51 * Verify the MAC on the Signal message. 52 * 53 * @return 1 if verified, 0 if invalid, negative on error 54 */ 55 int signal_message_verify_mac(signal_message *message, 56 ec_public_key *sender_identity_key, 57 ec_public_key *receiver_identity_key, 58 const uint8_t *mac_key, size_t mac_key_len, 59 signal_context *global_context); 60 61 int signal_message_is_legacy(const uint8_t *data, size_t len); 62 63 void signal_message_destroy(signal_type_base *type); 64 65 int pre_key_signal_message_create(pre_key_signal_message **pre_key_message, 66 uint8_t message_version, uint32_t registration_id, const uint32_t *pre_key_id, 67 uint32_t signed_pre_key_id, ec_public_key *base_key, ec_public_key *identity_key, 68 signal_message *message, 69 signal_context *global_context); 70 71 int pre_key_signal_message_deserialize(pre_key_signal_message **message, 72 const uint8_t *data, size_t len, 73 signal_context *global_context); 74 75 int pre_key_signal_message_copy(pre_key_signal_message **message, pre_key_signal_message *other_message, signal_context *global_context); 76 77 uint8_t pre_key_signal_message_get_message_version(const pre_key_signal_message *message); 78 ec_public_key *pre_key_signal_message_get_identity_key(const pre_key_signal_message *message); 79 uint32_t pre_key_signal_message_get_registration_id(const pre_key_signal_message *message); 80 int pre_key_signal_message_has_pre_key_id(const pre_key_signal_message *message); 81 uint32_t pre_key_signal_message_get_pre_key_id(const pre_key_signal_message *message); 82 uint32_t pre_key_signal_message_get_signed_pre_key_id(const pre_key_signal_message *message); 83 ec_public_key *pre_key_signal_message_get_base_key(const pre_key_signal_message *message); 84 signal_message *pre_key_signal_message_get_signal_message(const pre_key_signal_message *message); 85 86 void pre_key_signal_message_destroy(signal_type_base *type); 87 88 int sender_key_message_create(sender_key_message **message, 89 uint32_t key_id, uint32_t iteration, 90 const uint8_t *ciphertext, size_t ciphertext_len, 91 ec_private_key *signature_key, 92 signal_context *global_context); 93 int sender_key_message_deserialize(sender_key_message **message, 94 const uint8_t *data, size_t len, 95 signal_context *global_context); 96 int sender_key_message_copy(sender_key_message **message, sender_key_message *other_message, signal_context *global_context); 97 98 uint32_t sender_key_message_get_key_id(sender_key_message *message); 99 uint32_t sender_key_message_get_iteration(sender_key_message *message); 100 signal_buffer *sender_key_message_get_ciphertext(sender_key_message *message); 101 int sender_key_message_verify_signature(sender_key_message *message, ec_public_key *signature_key); 102 103 void sender_key_message_destroy(signal_type_base *type); 104 105 int sender_key_distribution_message_create(sender_key_distribution_message **message, 106 uint32_t id, uint32_t iteration, 107 const uint8_t *chain_key, size_t chain_key_len, 108 ec_public_key *signature_key, 109 signal_context *global_context); 110 int sender_key_distribution_message_deserialize(sender_key_distribution_message **message, 111 const uint8_t *data, size_t len, 112 signal_context *global_context); 113 int sender_key_distribution_message_copy(sender_key_distribution_message **message, sender_key_distribution_message *other_message, signal_context *global_context); 114 115 uint32_t sender_key_distribution_message_get_id(sender_key_distribution_message *message); 116 uint32_t sender_key_distribution_message_get_iteration(sender_key_distribution_message *message); 117 signal_buffer *sender_key_distribution_message_get_chain_key(sender_key_distribution_message *message); 118 ec_public_key *sender_key_distribution_message_get_signature_key(sender_key_distribution_message *message); 119 120 void sender_key_distribution_message_destroy(signal_type_base *type); 121 122 #ifdef __cplusplus 123 } 124 #endif 125 126 #endif /* PROTOCOL_H */ 127